Stb? Query (Status Byte); Trg Command (Trigger) - Iwatsu VOAC760 Manual

3.4.12  STB? query (Status Byte)
Here, the status byte and master summery status bit (MSS message) can be read.
Query syntax
 STB?
Response message <status>
<status> is a numeric value ranging from "0" to "249" in the <NR1 NUMERIC RESPONSE DATA>
format that the value of each bit in the status byte register is weighted by exponentiation of "2".
Remarks: Structure of status byte register
Bit
7
6
5
4
3
2
1
0
This instrument does not use bits 1 and 2. Therefore, even though all bits of this register are set at "1",
the maximum value of the response message becomes 249 (  128  64  32  16  8  1).
When the contents of the status byte register are read using the  STB? query, the MSS message is
used for bit 6 instead of RQS in conformity with the IEEE488.2 standard. Other bits become the same
values read by the serial polling.
The MSS message is obtained by logical OR of all bits except for bit 6 after the contents of the status
byte register are masked (logical AND) according to the contents of the service request enable
register.
The RQS message is basically retained in the status byte register until the serial polling is performed.
On the contrary, the MSS message affects the internal status of the instrument at real-time.
3.4.13  TRG command (Trigger)
When a trigger source is in BUS, the trigger is forced to generate.
When the instrument is trigger wait status, measurement is started.
Command syntax
 TRG
Remarks
In the case the instrument is not trigger wait status, it becomes an execution error.
Weighting Meaning
128 OPS- Operation event status
64 RQS/MSS-Request service/Message summary status
32 ESB- Event status
16 MAV- Message available
8 QES- Questionable event status
4 XXX- Since this instrument does not use this bit, the bit is
always set at "0".
2 XXX- Since this instrument does not use this bit, the bit is
always set at "0".
1 MEV- Measurement event status
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